Somewhat new to Calibre and the more I use it the more I need to learn!

It seems that I have one book in my library database that is causing a problem. Lets say that I have 100 books and this is book#50. I get a response from Calibre for #'s 1 - 49 and 51 - 100. I get NONE for #50. I cannot use the program to delete it because it does not recognize it. I added the book again to the library and it was done successfully, without presenting the usual window saying this book is already in library, do you want to add it. Again, because Calibre did not recognize it.

Thinking that it might be in the database I checked on this forum and found a couple of mentions about going to preferences + advanced + database. Well I found preferences+advanced but NO database.

In my original post I tried to explain that I tried that and it failed.

"I cannot use the program to delete it because it does not recognize it. I added the book again to the library and it was done successfully, without presenting the usual window saying this book is already in library, do you want to add it. Again, because Calibre did not recognize it."

The program is not recognizing this one book and when I do do click on the book the program does not respond, and soon I get a message that the entire program is not responding.

This occurs ONLY on this one book, all other book entries respond correctly.

"I cannot use the program to delete it because it does not recognize it. I added the book again to the library and it was done successfully, without presenting the usual window saying this book is already in library, do you want to add it. Again, because Calibre did not recognize it."

You actually see this book in your library?
When you select it what formats exist for this book? To find the formats select the book and click edit metadata and tell me what you see in available formats area (see attached).
What format is the book you try to add?
When you select the book and say remove is the entry deleted?
Did you reboot your computer and try to remove the book?

Dwanthy - thanks for your response. Since receipt of your response I defragmented my drives and then rebooted .................... same problem

You asked "You actually see this book in your library?" YES, I actually see the book in the library.

You asked "When you select it what formats exist for this book?" and "When you select the book and say remove is the entry deleted?"

I have tried to explain this previously.............. when I select the book nothing happens! As opposed to the normal response of highlighting the selected book in blue and then being able to select an action i.e delete book, edit book, view book.

What does happen is that the cursor changes to a spinning wheel and in a second or two a message stating "(not responding) appears at the top left and the only action I can take is to close the program and restart.

Not stating this as a cause but only an observation is that this began after I installed 7.25. I have since uninstalled and reinstalled but problem persists.

Kovid - yes, one of your forum members pointed this out in a previous response and in my response to him I stated "Manichean - thanks for pointing out the library maintenance drop down menu. I did run the database integrity check and it found no problems. So my problem still exists" (see above)

Kovid - yes, one of your forum members pointed this out in a previous response and in my response to him I stated "Manichean - thanks for pointing out the library maintenance drop down menu. I did run the database integrity check and it found no problems. So my problem still exists" (see above)

Did you run check_library (found near check integrity)? It won't fix anything, but it might point at where the problem is.